Reflection oscillators have been employed since the introduction of solid state devices into the realm of circuit design. Devices such as impatts, trapatts, and tunnel diodes are two terminal devices that reflect a negative conductance across their terminals, and, when connected across a low loss resonant circuit, will sustain oscillations. Bipolar and field effect transistors obtain a negative conductance by inserting a reactance at one terminal and, through the transistor's gyrator characteristic, reflect a negative conductance at another terminal. The third terminal is employed as an output terminal. The negative conductance may sustain oscillations when connected across a low loss resonant circuit. Such oscillators are usually employed in the microwave region and are not crystal controlled. Currently, however, a fundamental or overtone crystal is commonly employed in a grounded base configuration of a Colpitts oscillator. For a given frequency, the transistor is operated in the flat portion of its gain versus frequency curve, which is considerably lower than F.sub.t. This necessitates a relatively high frequency device, which is usually more costly. Alternatively, the F for such devices may be only increased by increasing the quiesient current.
Beyond 1 GHz, SAW resonators may extend the frequency range beyond the range of currently available crystals to 1.5 GHz. Beyond this frequency range, dielectric resonators (DRs) are now being employed up to 15 GHz. However, 15 GHz or 1.5 GHz SAW and DR oscillators have not achieved the stability of crystal oscillators. To achieve higher frequencies with crystal controlled oscillators, the current practice is to employ multipliers.